Olive oil serves as a fundamental fat source in many global cuisines and is celebrated for its health benefits, particularly within the Mediterranean diet. For individuals managing food sensitivities, concerns often arise regarding compounds that can trigger adverse reactions. One such concern centers on histamine, a naturally occurring chemical involved in immune response and neurological function. When the body cannot efficiently process ingested histamine, a condition known as histamine intolerance can lead to various uncomfortable symptoms, prompting a closer look at the histamine content of foods like olive oil.
The Measured Histamine Content
Fresh, high-quality Extra Virgin Olive Oil (EVOO) is inherently low in histamine and is usually well-tolerated by individuals following a restricted diet. Unlike many histamine-rich foods, which acquire high levels through microbial action, olive oil is a pure fat pressed directly from the olive fruit. This physical extraction process means the oil bypasses the bacterial fermentation or prolonged aging steps responsible for histamine production in items like cured meats or fermented vegetables.
Scientific assessments support this low-histamine classification, often rating olive oil as having negligible content. The oil’s composition is predominantly fatty acids, primarily oleic acid, rather than the free amino acids necessary for bacteria to produce significant biogenic amines. The inherent chemical makeup of a freshly pressed, unadulterated olive oil does not lend itself to significant histamine accumulation, making EVOO a safe and recommended dietary fat for those who must limit their histamine intake.
Related Compounds and Histamine Intolerance
Histamine intolerance is not a true allergy but indicates the body is struggling to break down normal levels of histamine consumed through food. This difficulty is often due to a deficiency in the enzymes responsible for histamine metabolism, primarily Diamine Oxidase (DAO) and, to a lesser extent, Histamine N-methyltransferase (HNMT). When DAO activity is insufficient, the histamine load from food accumulates, leading to allergy-like symptoms.
The complexity of olive oil lies in its interaction with the body’s detoxification system. Oleic acid, the main fatty acid in olive oil, has been shown to dramatically increase the release of the DAO enzyme into the bloodstream, which is generally beneficial for managing histamine. However, for individuals with extremely low DAO levels, some evidence suggests that this process may first involve a temporary, localized increase in histamine before the DAO is released. If the body cannot produce enough DAO to compensate, this initial surge might trigger symptoms in the most sensitive individuals.
Histamine is part of a broader group of compounds called biogenic amines, which includes tyramine, putrescine, and cadaverine. These other amines are also metabolized by DAO and compete with histamine for the enzyme, effectively increasing the overall histamine load. They can also enhance histamine toxicity, worsening symptoms. Since fresh EVOO is typically low in these other biogenic amines, it remains a safer choice compared to other fats derived from protein-rich sources or those that undergo microbial processing.
Quality and Processing Considerations
While the natural composition of olive oil is low in histamine, its stability and quality are paramount for sensitive individuals. The oil’s integrity can degrade through improper storage, introducing compounds that cause gut irritation. Oxidation, commonly referred to as rancidity, is the main concern, as it causes the breakdown of fatty acids and results in the formation of aldehydes and ketones.
These breakdown products, even if not histamine themselves, can irritate the digestive tract and trigger an inflammatory response that may lead to the secondary release of histamine in the gut. Heat, light, and air exposure accelerate this oxidation process. The age of the oil is also a factor, as the natural antioxidants in EVOO diminish over time, making older oil more susceptible to degradation.
Refining processes also impact the final product’s sensitivity profile. Refined olive oils, including blends often labeled simply as “olive oil” or pomace oil, have been found to contain higher histamine levels than true EVOO. This is partly because refining destroys the beneficial polyphenols that help maintain the oil’s stability. Therefore, to minimize the risk of a reaction, those with sensitivities should always choose a high-quality, cold-pressed Extra Virgin Olive Oil and store it in a cool, dark place in an opaque container.